Study One, ?Screening Guru? Abstract The adolescent suicide rate has increased by more than 20% in the past decade and is now the second leading cause of death for adolescents. Depression is the single most important contributor to suicidal ideation, attempt, and death by suicide among adolescents aged 12-17.11. Screening for mental health problems in general, and for depression and suicidality in particular, is a national priority. Even when routine screening is implemented, initiation of treatment is low. One critical barrier to starting depression treatment is whether adolescents and their parent(s) perceive a need for mental health treatment. Perceived need for mental health care services is a known predictor of service use, but may be low when depression is not the presenting concern but rather is identified on a routine screening questionnaire. This project seeks to increase the rate of appropriate referrals by primary care providers and treatment initiation among adolescents who screen positive for depression or suicidal ideation by: 1) assessing adolescents? and their parents? barriers to following through with clinician-recommended care prior to the start of treatment; and 2) providing clinicians with decision- support recommendations that are personalized to the adolescent?s clinical presentation, treatment preferences, and barriers. This will be accomplished through three specific aims. Aim 1 is to develop an automated decision-support system (DSS) that will guide primary care providers in making personalized treatment recommendations to adolescents presenting with symptoms of depression and risk for suicide at the time of the office encounter. Aim 2 is to test the effectiveness of the DSS, using a stepped wedge design, at increasing primary care providers? rate of personalized referrals in a pilot trial (N = 120) of adolescents aged 12-17.11 years who screen positive for depression and/or suicidality during a routine primary care visit. Aim 3 is to explore the impact of the DSS on service utilization and symptom reduction. This project is innovative because there currently is no support tool for PCPs assessing depressed adolescents, the tool integrates information about suicidal risk using an adaptive screen, severity of depression, and patient and parent motivation, barriers, and treatment preferences to provide the PCP with a personalized recommendation for the patient. The study has the potential to improve care following depression screening by reducing variability in PCPs? treatment recommendations, and increasing PCPs? awareness of potential barriers to care so as to provide a referral that reflects the patient?s clinical needs and also increases patients? engagement with recommended care.